Add missing macros in README and link to docs for more info

[nikhilreddydev]

As described in #4260, made below changes

1. Added missing macros in README and link to docs for more info
2. Added missing @brief macro tags
3. Changed order of non-intrusive macros to match intrusive macros
4. Added nav items for ...only_serialize macros in documentation

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Read the Contribution Guidelines for detailed information.

• Changes are described in the pull request, or an existing issue is referenced.
• The test suite compiles and runs without error.
• Code coverage is 100%. Test cases can be added by editing the test suite.
• The source code is amalgamated; that is, after making changes to the sources in the include/nlohmann directory, run make amalgamate to create the single-header files single_include/nlohmann/json.hpp and single_include/nlohmann/json_fwd.hpp. The whole process is described here.

[nikhilreddydev]

@nlohmann @gregmarr
I have added @brief macro tags but not sure about the @since tags
can you please let me know the versions to add.

[coveralls]

coverage: 99.639%. remained the same
when pulling 6365a58 on nikhilreddydev:develop
into a6255cc on nlohmann:develop.

[github-actions]

🔴 Amalgamation check failed! 🔴

The source code has not been amalgamated. @nikhilreddydev
Please read and follow the Contribution Guidelines.

[nlohmann]

I have added @brief macro tags but not sure about the @since tags can you please let me know the versions to add.

The version when the macro was added should be in the detail pages of the macros (see https://json.nlohmann.me/api/macros/ for an overview). If there is no version mentioned or the version is unknown, just add @since version 3.11.x.

[nlohmann]

Looks good to me.

[nlohmann]

Thanks! I will adjust the README in #4560.

[nikhilreddydev]

Thanks! I will adjust the README in #4560.

Sure.
Thank you for merging this. I'm happy to see my first contribution getting merged. Looking forward for more contributions.